1. Field
The present disclosure relates to systems for delivering a prosthesis to a desired location in the body of a patient and methods for delivering and implanting a prosthesis. More particularly, the present disclosure relates to prosthetic valve delivery systems for deploying a heart valve prosthesis within a body lumen and to methods of delivering and deploying such a prosthesis to a desired location in the body.
2. Background
Currently, replacement of a deficient cardiac valve is often performed by placing the patient under extracorporeal circulation, temporarily stopping the heart, opening the thorax (e.g., by a sternotomy), surgically opening the heart, excising the deficient valve, and then implanting a prosthetic valve in its place. This procedure generally requires prolonged patient hospitalization, as well as extensive and often painful recovery.
Recently, minimally invasive approaches have been developed to facilitate catheter-based implantation of valve prostheses in the beating heart, intending to obviate the need for the classic sternotomy and cardiopulmonary bypass. For example, U.S. Pat. No. 8,016,877 to Seguin et al. illustrates a technique and a device for replacing a deficient heart valve by percutaneous route. An expandable prosthetic valve can be compressed about a catheter, inserted inside a body lumen, such as the femoral artery, and delivered to a desired location in the heart. Additionally, U.S. Pat. No. 7,914,569 to Nguyen et al. discloses advancing a catheter containing a prosthesis in a retrograde manner through the femoral artery and into the descending aorta, over the aortic arch, through the ascending aorta and inside the defective aortic valve. This procedure can be assisted by fluoroscopic guidance. Once the position of the catheter containing the prosthesis is confirmed, a sheath containing the prosthesis can be moved proximally, allowing the valve prosthesis to self-expand.
Other techniques for delivering prosthetic heart valves via a catheter include transapical and trans-aortic approaches for aortic valve replacement, typically involving the use of an introducer port, i.e., a large-bore overtube, of a trocar. A crimped, framed valve prosthesis reversibly coupled to a delivery catheter can be transcatheterally advanced toward the native valve, where it can either be deployed using a balloon catheter, or, alternatively, using a self-expandable system.
With regard to the structure of the heart valve prosthesis itself, U.S. Pat. No. 7,914,569 to Nguyen et al. describes an example prosthesis for percutaneous transluminal delivery, and is incorporated by reference herein in its entirety. The heart valve prosthesis can have a self-expanding multi-level frame that supports a valve body with a skirt and plurality of leaflets. The frame can be contracted during percutaneous transluminal delivery and expanded to an hourglass shape upon deployment within the native heart valve.